Browsing by Subject "Computed axial tomography"

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    Reliability and diagnostic performance of CT imaging criteria in the diagnosis of tuberculous meningitis
    (Public Library of Science, 2012) Botha, Hugo; Ackerman, Christelle; Candy, Sally; Carr, Jonathan A; Griffith-Richards, Stephanie; Bateman, Kathleen J
    Introduction Abnormalities on CT imaging may contribute to the diagnosis of tuberculous meningitis (TBM). Recently, an expert consensus case definition (CCD) and set of imaging criteria for diagnosing basal meningeal enhancement (BME) have been proposed. This study aimed to evaluate the sensitivity, specificity and reliability of these in a prospective cohort of adult meningitis patients. METHODS: Initial diagnoses were based on the CCD, classifying patients into: ‘Definite TBM’ (microbiological confirmation), ‘Probable TBM’ (diagnostic score ≥10), ‘Possible TBM’ (diagnostic score 6-9), ‘Not TBM’ (confirmation of an alternative diagnosis) or ‘Uncertain’ (diagnostic score of <6). CT images were evaluated independently on two occasions by four experienced reviewers. Intra-rater and inter-rater agreement were calculated using the kappa statistic. Sensitivities and specificities were calculated using both ‘Definite TBM’ and either ‘Definite TBM’ or ‘Probable TBM’ as gold standards. RESULTS: CT scan criteria for BME had good intra-rater agreement (κ range 0.35-0.78) and fair to moderate inter-rater agreement (κ range 0.20-0.52). Intra- and inter-rater agreement on the CCD components were good to fair (κ  =  ranges 0.47-0.81 and 0.21-0.63). Using ‘Definite TBM’ as a gold standard, the criteria for BME were very specific (61.5%-100%), but insensitive (5.9%-29.4%). Similarly, the imaging components of the CCD were highly specific (69.2-100%) but lacked sensitivity (0-56.7%). Similar values were found when using ‘Definite TBM’ or ‘Probable TBM’ as a gold standard. DISCUSSION: The fair to moderate inter-rater agreement and poor sensitivities of the criteria for BME suggest that little reliance should be placed in these features in isolation. While the presence of the CCD criteria of acute infarction or tuberculoma(s) appears useful as rule-in criteria, their absence is of little help in excluding TBM. The CCD and criteria for BME, as well as any new criteria, need to be standardized and validated in prospective cohort studies.
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    Systematic review of antiretroviral-associated lipodystrophy: lipoatrophy, but not central fat gain, is an antiretroviral adverse drug reaction
    (Public Library of Science, 2013) de Waal, Reneé; Cohen, Karen; Maartens, Gary
    BACKGROUND: Lipoatrophy and/or central fat gain are observed frequently in patients on antiretroviral therapy (ART). Both are assumed to be antiretroviral adverse drug reactions. METHODS: We conducted a systematic review to determine whether fat loss or gain was more common in HIV-infected patients on ART than in uninfected controls; was associated with specific antiretrovirals; and would reverse after switching antiretrovirals. RESULTS: Twenty-seven studies met our inclusion criteria. One cohort study reported more lipoatrophy, less subcutaneous fat gain, but no difference in central fat gain in HIV-infected patients on ART than in controls. Randomised controlled trials (RCTs) showed more limb fat loss (or less fat gain) with the following regimens: stavudine (versus other nucleoside reverse transcriptase inhibitors (NRTIs)); efavirenz (versus protease inhibitors (PIs)); and NRTI-containing (versus NRTI-sparing). RCTs showed increased subcutaneous fat after switching to NRTI-sparing regimens or from stavudine/zidovudine to abacavir/tenofovir. There were no significant between-group differences in trunk and/or visceral fat gain in RCTs of various regimens, but results from efavirenz versus PI regimens were inconsistent. There was no significant between-group differences in central fat gain in RCTs switched to NRTI-sparing regimens, or from PI-containing regimens. CONCLUSIONS: There is clear evidence of a causal relationship between NRTIs (especially thymidine analogues) and lipoatrophy, with concomitant PIs possibly having an ameliorating effect or efavirenz causing additive toxicity. By contrast, central fat gain appears to be a consequence of treating HIV infection, because it is not different from controls, is not linked to any antiretroviral class, and doesn't improve on switching.